Railway-motor control.



110.784,814. l PATENTE-111111.14, 1905.

. O. y. STBINMETZ.

111111111111? MOTOR OONTROL.

APPLICATION FILED AUG. 20, 1904.

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DECIECICHIIII uw WMM!- la@ No. 784,814. RATRNTRD MAR. 14, 1905.

O. P. STRINMRTZ.

RAILWAY MOTOR CONTROL.

APPLIGATION FILED AUG. 20, 1904.

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No. 784,814. Patented March 14, 1905.

UNITED STaTes liaTienT FFICF.,

CHARLES l. STEINMETZ, CF SCllFNECTADY, NFV YORK, ASSIGNOR- TC GENERAL ELECTRIC CCh'IlANY, A CORPORATION CF NEW YORK.

RAlLWAYmlVlGTR CONTRGL.,

SPECIFICATION forming part o' Letters Patent No. 784,81, dated March 14, 1905.

.Application filed August 20, 1904. Serial No` 221,480.

fo all whom if; may oon/corn: and is what is known as a compensated7 50 Be it known that I, CnAnLus l). S'rnmnu'rz, series motor. Four ot these motors are shown a citizen of the United States, residing at in the ligure indicated by h'i, Mi, M, and M. Schenectady, inthe county ot' Schenectady and The motor M is provided with three sets oll State of New York, have invented certain new windings, the armature-wiwiing indicated by and useful Improvements in Railway-Heter A, awiinlingwhichlshallcallthe lield in- 55 Control, of which the following is a specilicadicated by F F, md il Winding' WhCh l Slmll tion. call the L compensating windingindicated by My invention relates to the control oiE elec- C C'. lt all these windings are connected in IO trie motors. and is particularly applicable to series, it will be seen that the current in the the control of railway-vehicles propelled by lield-wiinlings F F producesamagnetization 60 electric motors, though it is not limited to at right angles to that produced bythe armathis speciiic application. ture-winding A, and consequently produces a The object of my invention is to provide a torque therewith. The windings C' C, on the I5 novel and elicient control system by means other hand, produce a magnetization parallel oil which electric motors may be operated on to that produced by the armature-wimling A, 5 either alternating ordirect current. Although and consequently can exert no torque theredirect current has been used almost eXcluwith; but it' this winding is so connected that sively in the past Vfor electric railways, in the the current in each conductor is in the opposite 2O last few years alternating current has been direction to that in the adjacent conductor ol adopted for a number ot' railway-lines. On the armature-winding f the windings C C 70 account of its ease of transmission alternating will act to neutralize the armature reaction current is particularly adapted for long-disand Ator this reason are termed compensattance interurban lines. For lines within the ing77 windings. Theneutralization otl the arlimits of a city, however, alternating current mature reaction enables the motor to operate at a high potential is not suitable, and conseon direct current sparklessly with a weaker 75 quently it has been proposed to supply electric lield than would be otherwise possible. This p roads from two sources, one furnishing alterability to operate on a weak lield is oi' impornating current for use outside of cities and tance when the motor is operated on alternatthe other furnishing direct current for use ing current, since the number of iield turns.

within the city limits. lVhen such a system and consequently the self-induction oi the 30 is adopted, it, becomes important that a car ieldnnay be reduced and the power factor corshould be able to operate on either system. respondingly increased. Furthermore, when My invention consists in providing a novel the motor is operated on alternating current control system applicable to certain types ot' the compensating windings C C, it' connected motors and enabling' them to be operated el'liin series with the armature, serve elifectively 35 `ciently on either direct or alternating' current. l to neutralize its self-induction. The motor My invention will best be uinlerstood by may consequently be operated ou either direct reference to the accompanying drawings, in or alternating current, with the three wind- 40 whichings connected in series. This i'iecessitates,

Figure 1 shows diagrammatically a control however, that the direct and alternating vol- 90 system arranged in accordance with my intages from which the motor is supplied should vention. Fig. 2 shows a diagram ol connecbear a certain ratio to each other, lior there tions for the control ot' a single motor in acare delinite maximum voltages for both direct cordance with my invention, and Figs. 3 and and alternating current above which sparkless 4t show the connections for YFour motors prooperation is diliicult to secure, since the vol- 95 duced by the control system ol Fig. l. tage impressed upon the commutator cannot The type oi motor to which my invention be indelinitely increased. if, however, the relates is shown diagrammatically in Fig. 1 I compensating windings C C alone are connected to the source ot alternating current, while the armature-winding A and the lieldwindings F F are connected in series in a short circuit, the windings C C will act as theV primary ol'I a transformer to induce an electroi'notive lorce in the winding A, and the ratio ot' the electromotive torce impressed upon the compensating winding and induced in the armature-winding may be made anything desired by properly proportioning the relative nulnbel' oi' turns ot' the two windings. Consequently greater flexibility is obtained and higher alternating voltage may be used, while the current in the windings C C and in the winding A serve mutually each to neutralize the selli-imluctioii ot the other in the same manner as with the series connection.

My invention consists in the combination with one or morennotors ot' the type illustrated and described ot two sources ol direct and alternating current, respectively, and means `l'or connecting all three windings ol the motor or motors in series to the source ot direct current or lor connecting the compei'isating winding to the som'ce oll alternating current and short-circi'iiting the other two windings in series with each other. y My invention lurther consists in the combination, with the above, ol a variable resistance connected in the armature-circuit, by means ot whichthe speed ol the motor or motors may be varied.

Now referring to Fig. 2, the circuit connections for asingle motor will be readily understood. The lines l d represent a source ot direct current, and a, u represent a source ot' altern ating' curren t. A represents thearmature, F the lield, and C the compensating winding, o'tl a motor ot the type described. R represents a variable resistance, and S and S' represent switches, adapted, respectively, to connect the motor to the direct-current source or to the alternating-current source. s represents a reversing-switch, by means ot which the connections ot' winding F, and conseq uently the motor torque, may be reversed. \Yith the switch S closed, as shown, and the switch S open` the Afollowing circuit may be traced: from line-wire Z through switch S, resistance R, reversing-switch s, lield-winding F, armature A, switch S, compensating winding C, switch S, line-wire nl. lhe three windings are consequently connected in series and the motor operates as a direct-current compensated series motor. lVith switch S open and switch S closed the following circuit may be traced: from line-wire c, through switch S, compensating' winding C, switch S, line-wire (7,. Compensating winding C is consef'luently connected directly across the source ol'I alternating'-current voltage. A

second local circuit is closed as Follows: from the right-hand brush olI armature A, through reversing-switchs, lield F, resistance i, switch S, to the left-hand brush ot armature A. rlhe armature, Held-winding, and resistance are consequently connected in closed circuitit will be seen that with the motor connected either Jfor direct or alternating current the direction of rotation may be reversed by shifting the switch s, since the direction ol torque is reversed thereby. Furtherniore, the amount ol current-flow and the motor speed and torque may be regulated by varying the variable resistance R.

Evidently a plurality ot motors may be controlled by a single resistance. Such an arrangei'nentis shown in Fig. 3, in which lour motors are shown connected lor operation to a direct-current source, all switches being omitted. It will be seen that all lou r motors are connected in parallel between the line-wire /Z and the lelt-hand terminal ol resistance R, the three windings ol each motor being connected in series. Ry varying the resistamze R the speed and torque ol the lour motors may be simultaneously coiitrolled.

Fig. et similarly shows thel col'mections ol the same tour motors lor operation on alternating current. .lhe tour compensatingI windings (1 to C' are connected in series to the line-wires fr. a. The lield and armature ol each motor are connected in series, and the l'our armature-circuits are short-circuited in parallel through the resistance R. 'lhus with this comiection as with the other the speed and torque ot' the motors may be controlled by the one variable resistance. Reversingswitches tor the held-windings are indicated by the dotted lilies s to s" in both ligures. Ry comiecting the compensating \\'indings in series theI line-voltage is divided among` the motors.

\Vith the above explai'iation the arrangement ot' Fig. l will be clear. fl@ represents the controlling-switch, by means ol" which the four motors M to M" are com'iected vl'or operation on direct or alternating current and by means ot' which the variable amounts ol the resistance R are included in the motor-circuit, so as to control the speed and torque olE the motors. Evidently the two functions oli connecting' the motors for alternating or direct current and ot varying the amount ol resistance in the motor-circuits may be separated and performed by different switches, as in the arrangement ot' Fig. 2. G- represents the reversing-switch t'or varying the relative connections of the several lield-windings F to F, so as to vary the direction ol,5 rotation olI the motors.

It' the controlling-switch E is moved to bring the lett-hand set ol movable contacts in engagement with the stationary contact-lingers, and il the reversing-switch (el is closed in either direction-Mas, for instance by bringing the lett-hand movable contacts in engagement with the stationary contact-lingers--the 'l llowing circuits will be completed: One circuit maybe traced Vtrom line-wire u, contact ff,

IOO

contact e3, compensating winding C C, contact e, contact @22, compensating winding C2 C2, contact @15, contact @23, compensating winding C3 lg, contact @13, contact c2", compensating' winding C'L (1*, contact eu, contact e', line-wire a. The four compensating windings are consequently connected in series to the line, as shown in Fig. 4. The upper commutatorbrushes which form one terminal of the armature-windings and which are connected to contacts e c awt/1S are all connected through contact c to one terniinal ot' resistance R, the other terminal of which is connected, through the reversing-switch, to one terminal ot' the lieldwindings F to F4, the other terminals ol which are connected to the lower armature-b1'ushes through the reversing-switch. The connection of the armatures and fields is conseil ucntly that shown in Fig. 4, Vand as controllingswitch Eis moved through its several positions and the amount of resistance B. included in this short circuit is varied the speed and torque ot the motors may be controlled as desired. On the other hand, if the right-hand set of movable contacts are moved into eng'agement with the contact-lingers the following circuits are established: from line-wire (Z tln'ough contact-lingers @lo and c to one terminal of resistance R, the other terminal ot which is connected, through the reversing-switch (ur, to one terminal of all the field-windings, as has been heretofore traced. The other terminals of the field-windings are connected to the lower commutator-brushes of their several armatures through the reversing-switch G, while the upper commutator-brushes of the motors are each connected to one terminal ot' the compensating windings through switch E. The other terminals of the compensating windings are all connected, through contact-lingers (3 to ci, with the contact and thence through contact a" to line-wire rl'. rlhus the four motors are connected in the sanne manner as is shown in Fig. 3.

Although for the sake of simplicityT I have indicated the type of motor to which my invention applies by a bipolar Grammc-ring winding, it will be understood that my invention is applicable to a compensated series motor with any well-known form of winding and with any number of poles, and by the term compensated motor, as used ,in this specilication and in the appended claims, I mean a motor ot' thecommutator type, having two iieldwindings arranged, respectively, to produce magnetizations, one at an angle to and the other approximately parallel with the magnetization produced by the armaturewinding.

I do not desire to limit myself to the particular arrangement and connections here shown; but I aim in the appended claims to cover all modifications which come within the scope of my invention.

That I claim as new, and desire to secure by Letters Patent of the United States, is4

l. In combination with a "compensated motor having armature, vield and compensating windings, a source of direct current, a source of alternating current, means for connecting all three windings in series to said direct-current source, and means for connecting the compensating' winding to the alter-7 nating-current source and connecting the armature and licld windings in series in a closed circuit.

2. In combination with a Lconlpensatml motor having' armature, lield and compensating windings, a variable resistance, a source ot' direct current, a source ot' alternating current. means Afor connecting' all three windings and said resistance in series and to said direct-cm'- rent source, and means VFor connecting said compensating winding to said alternating-cu rrent source and for connecting said armature and tield windings and said resistance in a closed circuit.

3, In combination with a compensated" motor having armature, field and compensating' windings, a source of direct current, a source ot' alternating current, means `for connecting' all three windings in series to said direct-current source, means for connecting the compensating winding to the alternatingcurrent source and connecting the armature and tield windings in series in a closed circuit, and means for reversing the relative connections ot' said armature and lield windings.

4. In combination with a compensated motor having' armature, lield, and compensating. windings, a variable resistance, a source of direct current, a source ot' alternating current, means for connecting all three windings and said resistance in series and to said directcurrent source, means for connecting said com pensati ng winding to-sai'd alternating-current source and for connecting' said armature and tield windings and said resistance in a closed circuit, means tor varying the amount otl said resistance in circuit, and means for reversing the relative connections or' said armature and field windings.

5. In combination, a plurality of com pensated motors cach having armature, tield and compensating windings, a source ot' direct current, a source of alternating current, means for connecting said motors in parallel to said direct-current source with all three windings of each motor in series, and means for connecting said compensating windings in series to said alternating-current source and connecting the armature and ield windings of each motor in series with each other in a closed circuit.

6. In combination, a plurality of compensated motors each having armature, iield and compensatingwindings, a variable resistance, a source of direct current, a source oi alter- IIO IIS

nating current, means for connecting the motors in parallel with each other and in series with said resistance to said direct-current source, all three windings of each motor being connected in series, and means for connecting' said compensating windings to said alternating-current source and connecting' the armature and iield windings of each motor in series and connecting them in a closed circuit in parallel with the other motors and in series with said resistance.

7. ln combination, a plurality of compensated motors each having' armature, iield and compensating' windings, a variable resistance, a source of direct current` asource of alternating current, means Vfor connecting the inotors in parallel with each other and in series with said resistance to said direct-current source, all three windings of each motor heing connected in series, and means for connecting' said compensating windings in series to said alternating-current source and connecting' the armature and lield windings olf eaeh motor in series and connecting' them in a closed circuit in parallel with the other n10- tors and in series with said resistance.

ln witness whereof l have hereunto set my hand this 19th dayv of August, 190%.

CHARLES l). S"E1Ni\/ll 1'l"i. l'Vitnesses:

BENJAMIN B. HULL, H ELEN Oiufoiu). 

